s390x/virtio-hcall: Add range check for hypervisor call
The handler for diag 500 did not check whether the requested function
was in the supported range, so illegal values could crash QEMU in the
worst case.
Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
CC: qemu-stable@nongnu.org
diff --git a/hw/s390x/s390-virtio-hcall.c b/hw/s390x/s390-virtio-hcall.c
index ee62649..0e328d8 100644
--- a/hw/s390x/s390-virtio-hcall.c
+++ b/hw/s390x/s390-virtio-hcall.c
@@ -26,11 +26,14 @@
int s390_virtio_hypercall(CPUS390XState *env)
{
- s390_virtio_fn fn = s390_diag500_table[env->regs[1]];
+ s390_virtio_fn fn;
- if (!fn) {
- return -EINVAL;
+ if (env->regs[1] < MAX_DIAG_SUBCODES) {
+ fn = s390_diag500_table[env->regs[1]];
+ if (fn) {
+ return fn(&env->regs[2]);
+ }
}
- return fn(&env->regs[2]);
+ return -EINVAL;
}
